Hydrophilic dye cyanides-hydroxyalkyl compounds



United States Patent HYDROPHILIC DYE CYANIDES-HYDROXYAZKYL COMPOUNDSLyman Chalkley, Prince Georges County, Md.

No Drawing. Application July 5, 1957 Serial No. 669,931

20 Claims. (Cl. 204-158) The present invention relates to hydrophilicdye cyanides and, more particularly, to colorless hydrophilic dyecyanides of triphenylmethane dyes having at least one amino group parato the central methane carbon atom and at least one hydroxyalkyl radicalattached to the nitrogen atom of such amino group.

It has long been known that certain of the triphenylmethane dyes whichcontain at least one amino group para to the central methane carbon atomform colorless, or nearly colorless, cyanides which in the presence ofsuitable organic activators become photosensitive to ultraviolet andshorter wave lengths of light to produce colored compounds but which arenot sensitive to light in the visible range. Because of this property,the substances may be used in solution and absorbed or coated on asuitable base in the presence of an activator for the recording andmeasurement of ultraviolet radiation which has generally involved theuse of expensive equipment to isolate this region, such as quartzspectrographs and photoelectric meters.

Papers prepared from one of the photosensitive compounds and anactivator therefor may be used in photographic and photoduplicationprocesses to print out images that are fully formed without development,that may be permanent and that may be examined in ordinary interiorillumination without fixing. The papers employed retain theirultraviolet sensitivity after the printing of one image so that otherportions may be printed on at a later date.

However, all of the known p-amino triphenylmethane dye cyanides havebeen hydrophobic in nature and are not activated by water so as to bephotosensitive to ultraviolet and shorter wave lengths.

In my copending application, Serial Number 550,773, filed December 2,1955, now abandoned, I have disclosed that new compounds which comprisep-amino triphenylmethane dye cyanides having in the molecule at leastone hydrophilic group, such as the sulfonic acid, quaternary ammonium orhydroxyl group, are hydrophilic in character and that the potentialsensitivity to ultraviolet radiation possessed by the known hydrophobicdye cyanides is not lost in the new compounds. In fact, unlike theprevious hydrophobic p-amino triphenylacetonitriles, the new compoundsare activated by water alone. It will be understood, of course, thatmore than one type of hydrophilic group may be present in the samemolecule of dye cyanide. The p-amino groups may be primary, secondary,or tertiary in nature.

The present application relates to dye cyanides rendered hydrophilic bythe addition of hydroxyalkyl groups to the amino radicals, and is acontinuation-in-part of Serial Number 550,773. I have found that, unlikethe hydrophilic dye cyanides containing ammonium salts or sulfonicacids, the dye cyanides having one or more hydroxyalkyl amino groups arenonionic. While all hydrophilic .dye cyanides may be photoactivated byorganic activators such as were disclosed in U. S. Patent No. 2,676,887,r as well as by water, hydrocolloids, and the like, the ionic A2,877,169 Patented Mar. 10,

2 hydrophilic dye cyanides, such as those containing salts of sulfonicacids, are often quite insoluble in the non: aqueous types ofphotoactivators, and this insolubility presents obstacles to theirpractical use in hydrophobic systems. The non-ionic hydrophilic dyecyanides of the present invention, however, are soluble in a widevariety of organic photoactivators as well as having the prop ertycommon to hydrophilic dye cyanides of being photoactivated by water andhydrocolloids.

Aside from their utility in aqueous and hydrocolloid systems, thehydroxyalkyl dye cyanides have marked advantages for use in hydrophobicsystems because they are generally more soluble in nonaqueousphotoactivat ing solvents than are their simple alkyl counterparts, suchas Crystal Violet cyanide and Brilliant Green cyanide, which yieldsimilar colors on photolysis.

Another advantage of the dye cyanides of the present application is thatthey provide a continuous series of photosensitizers capable of printingimages varying in hue from a reddish magenta through the various degreesoi magenta, purple, violet blue and blue green, all with the commonproperty of photoactivation by a wide range of hydrophilic andhydrophobic photoactivators.

Accordingly, it is the object of the present invention to provide newtriphenylacetonitriles having at least one amino group para to thecentral methane carbon atom which are hydrophilic and are activated,when dissolved in or wet with water, to form colored compounds onexposure to ultraviolet and shorter wave lengths.

Another object of the present invention is to provide new hydrophilicdye cyanides which are non-ionic and are soluble in a wide variety ofsolvents and photoactivators.

A further object of the invention is to provide a photochemical processutilizing the new hydrophilic dye cyanides.

A still further object of the invention is to provide methods for theproduction of the novel hydroxyalkylated p-amino dye cyanides and ofmixtures of isomers and homologues thereof.

An example of the new type of dye cyanide is N,N,N',N',N",N"-hexa(pi-hydroxyethyl)-p-rosaniline cyanide. When pure, this is a colorless,microcrys talline solid. It does not have a sharp melting point becauseit is decomposed by heat. When heated rapidly to 200 C., where itsinters, and then slowly, the com: pound melts at 206-208 C., withdecomposition, to a black viscous liquid, which becomes more fluid onfurther heating. The compound is soluble in 2500 times its weight ofboiling water and something over 50,000 times its weight of water at 20C. It may be recrystallized from water, i-propyl alcohol and the like.Paper sensitized with the compound and dimethylformamide according tothe disclosure of my copending application Serial Number 648,791, printsout a blue-violet image on irradiation with ultraviolet of wave lengthsshorter than 3400 A. The absorption band of the dye forming this imageis unsymmetrical and falls off more sharply on the long wave length sidethan on the short wave length side. As a result, the hue of the imagevaries somewhat with the depth of image, becoming redder as the imagebecomes darker. In the Munsell notation,,a characteristic image hue isapproximately 7.5 PB at a value of 6-7.

The substances intermediate between the compound described above and theparent unalkylated p-rosaniline cyanide contain from one to fivehydroxyethyl substituents on the amino groups, and on photolysis yieldcolors ranging from magenta to violet, depending on the number ofhydroxyethyl groups in the molecule. These substances are lesscrystalloidal, tend to form amorphous solids, especially in mixtures,and colloidal suspensions in aqueous solvents. For these reasons, theseintermediate hydroxyethyl derivatives are often preferable for thepreparation of photosensitive systems with hydro colloids in which highconcentrations can be maintained without formation of the largeraggregates in which the hexa-(B'hydroxyethyl)-p-rosani1ine cyanidecrystallizes so readily.

While the hydroxyethyl group is quite satisfactory for the formation ofhydrophilic dye cyanides, other hydroxyalkyl groups such ashydroxypropyl, chlorohydroxypropyl and dihydroxypropyl, may be used.

The hydroxyalkyl dye cyanides may be prepared by the action of an alkalicyanide upon the corresponding hydroxyalkyl dye. However, for theproduction of photo- Sensitizers for practical use, I prefer to preparethem by the hydroxyalkylation of the primary amino dye cyanides becausethis method provides generally a mixture of isomers whose aggregatesolubility is greater than that of the individual molecular species. Thesyntheses may be carried out by the use of the conventionalhydroxyalkylating agents, such as ethylene oxide, propylene oxide,glycide, epichlorohydrin, and other alkylene oxides, ethylenechlorohydrin and other chlorohydrins.

The hydrophobic dye cyanide prototypes from which the hydrophilichydroxyalkyl dye cyanides may be considered to be derived, arepreferably the para diarnino and triamino triphenylacetonitriles, suchas 4,4'-diaminotriphenylacetonitrile, 4,4',4", triamino triphenylacetonitrile, 4,4,4" triamino 3 methyl triphenylacetonitrile,4,4',4"-triamino-3,3',3"-trirnethylacetonitrile.

The new hydroxyalkyl dye cyanides disclosed herein are represented bythe following general formula:

N/Rl

X X X wherein R and R have the meaning defined above. R and R maycomprise either the same or different groups or may be differentisomeric forms of the same general group.

The nature of the hydrophilic dye cyanides may be clearer from thefollowing examples, which are carried out in the absence of ultravioletradiation.

Example 1 A solution of 5 g. of 4,4,4"-triamino-triphenylaceto nitrile,in 100 m1. of ethylenechlorohydrine is boiled under a reflux condenserfor one-half hour. After the refluxing, 80 to 85 m1. of theethylenechlorohydrine is distilled off. The residue in the still isdissolved in '100 ml. of water and treated with a solution of g. ofsodium carbonate monohydrate in 50 ml. of water, whereupon thehydroxyethylated p-rosaniline cyanide is precip- .itated as an amorphousmass. This is washed with 50 ml. of water and air-dried or dried invacuo over suliuricacid. The dry material is little sensitive ot radia'tion. It is primarily tri-fl-hydroxyethyl-p-rosaniline cyanide and is amixture of compounds having the formulae In combinations with water andalcohols it gives photo sensitive systems that produce a reddish purplecol r on irradiation with ultraviolet,

Example 2 A solution of 5 g. of the product of Example 1 in 100 ml. ofethylencchlorohydrine is boiled under a reflux condenser for one-halfhour and .80 to ml. of the solvent distilled off as in Example 1. Theresidue is dissolved in ml. of water and the dye cyanide precipitated bythe addition of a solution of 10 g. of sodium carbonate monohydrate in50 ml. of water. The precipitated amorphous material is washed with alittlewater and dried. It is largely hexa-p-hydroxy-ethyl p-rosanilinecyanide having the formula PMC2114 11): (CaH.tO )1 NCCQL H):

It forms photosensitive systems that yield a blue-violet color onirradiation with ultra-violet.

In both of the above examples the period of heating withethylenechlorohydrine may be reduced to give less highlyhydroxyethylated forms than the final products of the examples, andthese yield .on irradiation of their photosensitive systems colors thatare redder than those produced by the compounds described in Examples 1and 2.

These compounds may also be prepared by the reaction of p-rosanilinecyanide with ethylene oxide, preferably in presence of water, which actsas a catalyst, with or without an inert solvent, such as triethylphosphate. This reaction generally gives higher yields of the purehexa-fi-hydroxyethyl-p-rosaniline cyanide, whose properties weredescribed earlier in this specification. Similar alkylene oxidereactions are illustrated in Examples 4, 5, 6 and 7 below.

Example 3 Three g. of finely powdered rosaniline cyanide is ausn nded ina mix re of -9 m1. of hy ne chlorohydrin chloride solution and allowedto stand overnight. The solution is then filtered through infusorialearth to remove an amorphous brown material and the filtrate made weaklyalkaline with ml. of 1.6 N sodium carbonate solution, which produces avoluminous, lightcolored, curdy precipitate. After'standing overnight,the precipitate is collected on a filter and washed with water. The wetmaterial has properties of an emulsion and, if warmed, readilysynerizes, releasing water and forming a residue which dries to abrittle, glassy material. If, however, the wet precipitate is dried in avacuum desiccator over sulfuric acid at a temperature not above C., itforms a friable mass that is easily broken up into a powder. This, formost purposes, is more convenient to handle than theglassy form. Thematerial is largely trihydroxyethyl 4,4',4" triamino 3 methyltriphenylacetonitrile, which occurs in several isomeric forms:

Example 4 To a solution of 2.5 g. of p-rosaniline cyanide in 100 ml. ofpropylene oxide at 25 C. is added 5 ml. of water. The mixture is kept ina closed flask for 5 weeks at 20 C. The excess propylene oxide is thenevaporated from a. water bath heated to 50 C. To the residual reactionproduct and water is added 3 ml. of concentrated hydrochloric acid and 3ml. of water, and the mixture stirred at 25 C. until the dye cyanide hasdissolved. The so lution is filtered, diluted with three times itsvolume of water, cooled to 10 C. and made alkaline with ammo niumhydroxide to precipitatethe. dyexoyanidc. The precipitation is carriedout in the cold so as to obtain the curdy type of precipitate describedin Example 3 rather than a tar. The precipitate, which will synerize andleave a glassy product if warmed, is dried in a vacuum desiccator oversulfuric acid at 20 C. It consists largely oftetra-fl-hydroxypropyl-p-rosaniline cyanide, which exists in theisomeric forms:

N(-cmoHOH-cm)i (IJN H-N-OHr-CHOH-C Hr H-N-CHr-OHOH-CH:

(In addition to the major p-hydroxypropyl derivatives, there is alsoformed some fi-hydroxypropyl compound with the amino groups attached tothe 3 carbon atom, and mixtures of the two in one molecule giving smallquantities of many isomers.)

The product forms photosensitive systems with hydro colloids, and alsowith oily photoactivators, which yield a violet color on irradiationwith ultraviolet.

Example 5 Ten g. of rosaniline cyanide is dissolved at 25 C. in 250 ml.of propylene oxide, and 10 ml. of water is added to'the solution. Themixture is kept in a sealed flask at 20? for 5 weeks. The excesspropylene oxide is then evaporated from a water bath heated to 50 C. Theresidue is dissolved in a mixture of 10 ml. of concentrated hydrochloricacid and 10 ml. of water at 25 C. The solution is filtered, diluted with3 times its volume of water, cooled to 10 C., and made alkaline withammonium hydroxide. After standing overnight the precipitate iscollected on a filter, washed withiwater and dried in a vacuumdesiccator over sulfuric .acid. The product is largely di-hydroxypropylrosaniline cyanide containing with smaller quantities of other isomers,such as? g in CH: N tilH-CH:OH 2

'8 along withthe corresponding p-r'oseniline cyanide derivalives.resulting from the p-rosamline always present in the commercialrosaniline as well as small amounts of 1 the monoand tri-propanolderivatives.

' The product formsphotosensitivesystems with hydro I colloids, and alsothe hydrophobic photoactivators, which print out a. magenta color onexposure to ultraviolet.

It will; be noted that in this example a smaller proportion of water wasused in the reaction mixture than in Example 4. Since water catalyzesthe reaction, the small proportion resulted in a lower reaction rate anda less highly hydroxypropylated product than in the preceding example.

Example 6 Ten g; ofthe cyanide of New Fuchsine, Color Index I Not 678,prepared as disclosed in my copending' patent I application SerialNumber 594,687, now Patent No. 2,-

25 'C. and mixed with '20 ml; of water.

used in the preceding example.

The solution is kept in a sealed flask at 20 C. for" 5 weeks. Thepropylene oxide is then distilled ofi at C; 'Theresidue is dissolved ina mixtureof 10 ml.

of concentrated hydrochloric acid and :20 ml. of water.

The solution is diluted with twice its volume of water and filtered. Thefiltrateis cooled in an ice bath, made alkaline with ammonium hydroxide,and'allowed to stand overnight. The precipitate is collected, washedwith water and dried-in vacuo over sulfuric acid at room temperature. Itis largely the tctrapropanol derivative of New Fuchsine cyanide,containing mianly the isomers.

I CN

with smaller quantities of other isomers, such as,

CH2 CH: CH:

- reflux condenser for six hours. The p-rosaniline cyanide l 9 e 10 aon, ml. of violently stirred water at 20 C., whereupon aeurdglprecipitate forms due to the hydrolysis of the by droc oride ofthe only slightly basic hexachloropropanolp-rosaniline cyanide. Thisprecipitate, like those in pre- N(GHz-CHOHCH:): ceding examples, shouldbe handled at not above room temperature if it is to be dried to areadily powdered -C s -'CHI C a solid rather than a glassy material.After standing overnight, the precipitate is collected on a filter,washed with water and dried in a vacuum desiccator over powdered sodiumhydroxide. The product is primarily 10 4 m-cni-onon-omcm I CH3N(CHiCHOHCHzOl)a m-omcnon-cmcn- N(CH3CHOH-CHI) CH] CH: CH]

I 0 ON on and some triand pentapropanol derivatives. with Smallerquantities of isomers such v cmcnon-cmci CHxOHOH-CHsCl ntom-cnon-cmom IfCHCHr-OH oncmon 0 $3101 t sniol CHICHOHCBICI m-cm-cnon-omct).N(-CH=-OHOHCH:C1),

cH'-CHlH lThe color developed by ultraviolet irradiation of mix- Thephewsensifive systems with gelatin and q' tures with hydroeolloids orother photoactivators is violet.

v by ultraviolet.

Example 8 Example 7 55 Five g. of the product of Example 7 is refluxedin 250 ml. of 4 N aqueous sulfuric acid for hours. The Fwe of Powdered pmsamlme cyamde of solution is diluted with 500 ml. of water, cooled to0? .epichlomhydrin 20 of 91% aicohol and 5 C. and neutralized with asolution of g. of sodium ml. of water are mixed and the liquid boiledunder a 0 hydroxide in 200 of water also cooled to vThe resultingmixture is held in an ice bath for an hour, the

all goes into Solution during the first hour of boilingcurdy precipitatecollected on a filter, washed with water The solution is transferred toa distilling flask with 10 and dried in a vacuum desiccator oversulfuric acid.

ml. of 91% i-propyl alcohol, and 30 ml. of water added. The Product islargely The addition of the water precipitates an oily material. 2 )2The remaining epichlorohydrin and solvents are then N(CHr-CHOHCH:OH)

vacuum distilled under a pressure of 3 cm. of mercury, MCHPCHOIFCEOH),

the temperature of the flask being raised gradually to i 1 C.

Twenty m1. of concentrated hydrochloric acid and 3 70 ml. of water areadded to the residue in the flask and c l 6N stirred gently at 25 C.until the resinous solid has dissolved to form a syrupy liquid. Solutionmay require H v up to 12 hours. The solution is then poured into 800 '75ous photoactivators print out a blue color on irradiation and containssmall quantities of such isomers as With hydrocolloids this productgives clear films that print a blue image. I

Other procedures will suggest themselves to those skilled in the art.Thus, higher temperatures and pressures may be employed to acceleratethe hydroxyalkylation reactions, glycide may be employed instead of thecheaper epichlorohydrin to produce the product of Example 8 directlywithout going through the intermediate chloropropanol derivative, etc.

Likewise, other homologous compounds may be prepared. Thus,N,N,-di-}3-hydroxyethyl aniline can be condensed in the usual way withbenz'aldehyde to produce bis-di-fl-hydroxyethylaminotriphenylmethane,which on oxidation yields the green dye N,N,N',N' -tetra-B-hydroxyethylDoebners Violet. This, by reaction with sodium cyanide, yields the dyecyanide l C which on photolysis in presence of a photoactivator yields agreen color. Other homologs are also readily pre pared.

All of the hydroxyalkyl p-amino dye cyanides disclosed herein are bothhydrophilic and non-ionic, may be activated by water alone, and formphotosensitive com binations with hydrocolloids as well as withphotoactivating hydrophobic systems. All forms of the new com poundsprovide photosensitive systems that responds to 3300 A. and shorter wavelengths.

It will be understood that the individual compounds of the productproduced by hydroxyalkylation of the pamino dye cyanides may beseparated from each other by known separation methods if desired, e. g.,by chromatography.

The present application is a continuation-in-part of my copendingapplication Serial Number 550,773, filed December 2, 1955, nowabandoned, and of my copending application Serial Number 542,479, filedOctober 24, 1955, now Patent No. 2,855,303.

I claim:

1. A hydrophilic cyanide of a p-amino triphenylmethane dye having atleast one hydroxy lower alkyl radical attached to the nitrogen atom of ap-amino group.

2. A hydrophilic cyanide having the formula wherein X is selected fromthe class consisting of hydrogen and a methyl group; R is selected fromthe class consisting of a lower alkyl group having at least one hydroxysubstituent, and a lower alkyl group having at least one hydroxy and atleast one halogen substituent; R, is selected from the class consistingof hydrogen and of the members of the class from which R is selected;and Y is selected from the class consisting of hydrogen, -NH,,

wherein R and R have the meaning defined above.

3. P-rosaniline cyanide having at least one hydroxy lower alkyl radicalattached to the nitrogen atom of a 11- amino group.

4. Rosaniline cyanide having at least one hydroxy lower alkyl radicalattached to the nitrogen atom of a p-amino group.

5. The cyanide of New Fuchsine, Color Index No. 678, having at leastonehydroxy lower alkyl radical attached to the nitrogen atom of a p-aminogroup.

6. A hydrophilic dye cyanide composition comprising a mixture of isomersof p-amino triphenylacetonitrile having at least one hydroxy lower alkylradical attached to the nitrogen atom of a p-amino group.

7. Hexa-(p-hydroxyethyl)-p-rosaniline cyanide.

8. Tri-(fi-hydroxyethyl)-p-rosaniline cyanide.

9. Tri-(fl-hydroxyethyl)-rosaniline cyanide.

10. Tetra-(hydroxypropyl)-p-rosaniline cyanide.

11. Di-(hydroxypropyl)-rosaniline cyanide.

l2. Tetra-(hydroxypropyl)-New Fuchsine cyanide.

13. Hexa (chlorohydroxypropyl) p rosaniline cyanide.

14. Hexa-(dihydroxypropyl)-p-rosaniline cyanide.

15. Tetra (B hydroxyethyl) diamino triphenylacetonitrile.

16. The method of preparation of a hydrophilic dye cyanide, comprisingsubjecting a p-amino-triphenylacetm nitrile having a halogeno loweralkyl substituent on at least one amino group to hydrolysis in aqueousacid to change the halogen-alkyl substituent to an hydroxy lower alkylsubstituent while leaving the nitrile group intact.

17. The process of forming a colored compound, comprising irradiatingwith ultraviolet energy in the presence of an activator, a hydrophiliccyanide of a p-amino triphenylmethane dye having at least one hydroxylower alkyl radical attached to the nitrogen atom of a p-amino group.

18. The process of forming a colored compound, comprising irradiatingwith ultraviolet energy in, the pres ence of an activator a hydrophiliccyanide having the formula N/Rr X X X wherein X is selected from theclass consisting of hy' drogen and a methyl group; R; is selected fromthe class consisting of a lower alkyl group having at least one hydroxysubstituent, and a lower alkyl group having at least one hydroxy and atleast one halogen substituent; R is selected from the class consistingof hydrogen and of the members of the class from which R; is selected;and Y is selected from the class consisting of hydrogen, NH and whereinR; and R, have the meaning defined above.

19. The process of forming a colored compound, comprising irradiatingwith ultraviolet energy in the presence of an activator,hexa-p-hydroxyethyl-p-rosaniline cyanide.

20. The process of forming a colored compound, com- 14 prisingirradiating in the presence of an activator consisting of water ahydrophilic dye cyanide of a p-amino triphenylmethane dye having atleast one hydroxy lower alkyl radical attached to the nitrogen atom of ap-amino group.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Fieser et aL: Organic Chemistry, 3rd ed., page 575.

18. THE PROCESS OF FORMING A COLORED COMPOUND, COMPRISING IRRADIATINGWITH ULTRAVIOLET ENERGY IN THE PRESENCE OF AN ACTIVATOR A HYDROPHILICCYANIDE HAVING THE FORMULA